Visit an online classifieds Web site, and you'll find a fleet of them: cars, trucks and motorcycles of all types, with outrageously low asking prices and long descriptions of the vehicles' excellent condition and luxury features. But mixed into the glowing descriptions of vehicle histories are two words that can quickly throw a complicating wrench into your dreams of finding the auto deal of the century: "salvage title." What does it mean when a car has a salvage title? Can the car be driven on the street? Is it even safe to drive a salvage-titled vehicle? Depending on the situation and your state's laws, a salvage title can mean a number of things: It could add time and expense to the licensing and registration process. It could kill the deal outright, leaving you searching for another car to buy. But in some cases, it could present a deal -- if you have the knowledge and mechanical know-how to take advantage of it. So what is a salvage title? State motor vehicle bureaus issue…